twickenham.c

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/********************************************************************\

  Name:         twickenham.c
  Created by:   Andreas Suter  2001/09/13

  Contents: device driver for the twickenham depth indicator.

  RS232:    9600 baud, 8 data bits, 1 stop bit, no parity bit
  protocol: Xon/Xoff (Software), termination: "\r\n"

\********************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include "midas.h"
#include "twickenham.h"

#include "ets_logout.h"

/*---- globals -----------------------------------------------------*/

#define TWICKENHAM_ETS_LOGOUT_SLEEP 10000

// --------- to handle error messages ------------------------------

#define TWICKENHAM_READ_ERROR -1  

#define TWICKENHAM_DEBUG FALSE    

#define TIME_OUT_TWICKENHAM 2000

#define TWICKENHAM_MAX_READBACK_FAILURE 5

typedef struct {
  INT   detailed_msg;      
  INT   ets_in_use;        
  char  name[NAME_LENGTH]; 
} TWICKENHAM_SETTINGS;

#define TWICKENHAM_SETTINGS_STR "\
Detailed Messages = INT : 0\n\
ETS_IN_USE = INT : 1\n\
Name = STRING : [32] HDI_Level\n\
"

typedef struct {
  TWICKENHAM_SETTINGS twickenham_settings; 
  INT   num_channels;                      
  INT (*bd)(INT cmd, ...);                 
  void *bd_info;                           
  HNDLE hkey;                              
  INT   errorcount;                        
  DWORD lasterrtime;                       
  int   bd_connected;                      
  INT   readback_failure;                  
  DWORD last_reconnect;                    
  float last_value;                        
  int   reconnection_failures;             
} TWICKENHAM_INFO;


/*---- device driver routines --------------------------------------*/

INT twickenham_init(HNDLE hKey, void **pinfo, INT channels, INT (*bd)(INT cmd, ...))
{
  int       status;
  char      str[256];
  HNDLE     hDB, hkeydd;
  TWICKENHAM_INFO       *info;

  cm_get_experiment_database(&hDB, NULL);

  // allocate info structure
  info = calloc(1, sizeof(TWICKENHAM_INFO));
  *pinfo = info;

  // create Twickenham settings record
  status = db_create_record(hDB, hKey, "DD", TWICKENHAM_SETTINGS_STR);
  if ((status != DB_SUCCESS) && (status != DB_OPEN_RECORD)) {
    cm_msg(MERROR, "twickenham_init", "twickenham_init: Error creating DD record in ODB, status=%d", status);
    cm_yield(0);
    return FE_ERR_ODB;
  }

  // Hot-link onto the device driver ODB entry (private stuff of the device driver)
  db_find_key(hDB, hKey, "DD", &hkeydd);
  db_open_record(hDB, hkeydd, &info->twickenham_settings, sizeof(info->twickenham_settings), MODE_READ, NULL, NULL);

  // initialize driver
  info->num_channels          = channels;
  info->bd                    = bd;
  info->hkey                  = hKey;
  info->errorcount            = 0;
  info->lasterrtime           = ss_time();
  info->bd_connected          = 0;
  info->readback_failure      = 0;
  info->last_reconnect        = ss_time();
  info->reconnection_failures = 0;

  if (!bd)
    return FE_ERR_ODB;

  // initialize bus driver
  status = info->bd(CMD_INIT, info->hkey, &info->bd_info);
  if (status != SUCCESS)
    return status;
  info->bd_connected = 1;

  // initialize Twickenham, check sensor status
  printf("\n initialize Twickenham.");
  BD_PUTS("S\r\n");
  status = BD_GETS(str, sizeof(str), "\r\n", TIME_OUT_TWICKENHAM);
  if (TWICKENHAM_DEBUG) {
     cm_msg(MINFO,"twicken_init", "status = %d, str = %s, device = %s",
            status, str, info->twickenham_settings.name+0);
     cm_yield(0);
  }
  if ( !status ) { // error occurred
    cm_msg(MERROR,"twickenham_init",
           "Error getting device status from Twickenham, %s",
           info->twickenham_settings.name+0);
    cm_yield(0);
    return FE_SUCCESS; //FE_ERR_HW;
  }
  cm_msg(MINFO,"twickenham_init", "Device status of Twickenham %s = %s", info->twickenham_settings.name+0,str);
  cm_yield(0);

  return FE_SUCCESS;
}

/*----------------------------------------------------------------------------*/
INT twickenham_exit(TWICKENHAM_INFO *info)
{
  // call EXIT function of bus driver, usually closes device
  info->bd(CMD_EXIT, info->bd_info);

  free(info);

  return FE_SUCCESS;
}

/*----------------------------------------------------------------------------*/
INT twickenham_get(TWICKENHAM_INFO *info, INT channel, float *pvalue)
{
char  str[128];
INT   status=0;

  if (info->bd_connected) {
    // read sensor level
    BD_PUTS("G\r\n");
    status = BD_GETS(str, sizeof(str), "\r\n", TIME_OUT_TWICKENHAM);
  }

  if (status != 0) {
    str[strlen(str)-2] = '\0';  // truncate mm ?
    if ( strstr(str, "-") )     // not a level message
      *pvalue = (float) TWICKENHAM_READ_ERROR;
    else { // standard level message
      sscanf(str+strlen(str)-6, "%f", pvalue); // to skip over the first characters
      info->last_value = *pvalue;
      info->readback_failure = 0;
    }
  }
  else {
    *pvalue = info->last_value;

    if (info->reconnection_failures > 5) {
      if (info->reconnection_failures == 6) {
        cm_msg(MERROR, "twickenham_get", "too many reconnection failures, bailing out :-(");
        info->reconnection_failures++;
      }
      return FE_SUCCESS;
    }

    // try to disconnect and reconnect the bus driver
    if ((ss_time()-info->last_reconnect > 10) && info->bd_connected) { // disconnect bus driver
      info->bd(CMD_EXIT, info->bd_info);
      if (info->twickenham_settings.detailed_msg)
        cm_msg(MINFO, "twickenham_get", "twickenham: try to disconnect and reconnect the bus driver");
      info->last_reconnect = ss_time();
      info->bd_connected = 0;
      if (info->twickenham_settings.ets_in_use)
        ets_logout(info->bd_info, TWICKENHAM_ETS_LOGOUT_SLEEP, info->twickenham_settings.detailed_msg);
    }

    info->readback_failure++;

    if (info->readback_failure == TWICKENHAM_MAX_READBACK_FAILURE) {
      info->readback_failure = 0;
      // try to reconnect after a timeout of 10 sec
      if ((ss_time()-info->last_reconnect > 10) && !info->bd_connected) {
        if (info->twickenham_settings.detailed_msg)
          cm_msg(MINFO, "twickenham_get", "twickenham: reconnection trial ...");
        status = info->bd(CMD_INIT, info->hkey, &info->bd_info);
        if (status != FE_SUCCESS) {
          if (info->twickenham_settings.detailed_msg)
            cm_msg(MINFO, "twickenham_get", "twickenham: reconnection attempted failed");
          info->reconnection_failures++;
          return FE_ERR_HW;
        } else {
          info->bd_connected = 1; // bus driver is connected again
          info->reconnection_failures = 0;
          info->last_reconnect = ss_time();
          if (info->twickenham_settings.detailed_msg)
            cm_msg(MINFO, "twickenham_get", "twickenham: successfully reconnected");
        }
      }
    }
  }
  ss_sleep(10);
  if (TWICKENHAM_DEBUG)
    cm_msg(MINFO,"tw_get","status = %d, str = %s, %f", status, str, *pvalue);
  return FE_SUCCESS;
}

/*----------------------------------------------------------------------------*/
INT twickenham_get_label(TWICKENHAM_INFO *info, INT channel, char *name)
{
  strcpy(name, info->twickenham_settings.name);

  return FE_SUCCESS;
}


/*---- device driver entry point -----------------------------------*/
INT twickenham(INT cmd, ...)
{
va_list argptr;
HNDLE   hKey;
INT     channel, status;
void    *info, *bd;
float   *pvalue;
DWORD   flags;
char    *name;

  va_start(argptr, cmd);
  status = FE_SUCCESS;

  switch (cmd)
    {
    case CMD_INIT:
      hKey    = va_arg(argptr, HNDLE);
      info    = va_arg(argptr, void *);
      channel = va_arg(argptr, INT);
      flags = va_arg(argptr, DWORD);
      bd      = va_arg(argptr, void *);
      status  = twickenham_init(hKey, info, channel, bd);
      break;

    case CMD_EXIT:
      info = va_arg(argptr, void *);
      status = twickenham_exit(info);
      break;

    case CMD_SET:
     break;

    case CMD_GET:
      info = va_arg(argptr, void *);
      channel = va_arg(argptr, INT);
      pvalue  = va_arg(argptr, float*);
      status = twickenham_get(info, channel, pvalue);
      break;

    case CMD_GET_LABEL:
      info = va_arg(argptr, void *);
      channel = va_arg(argptr, INT);
      name  = va_arg(argptr, char*);
      status = twickenham_get_label(info, channel, name);
      break;


    default:
      break;
    }

  va_end(argptr);
  return status;
}
/*------------------------------------------------------------------*/